FunBrain is a popular site for online educational games for K-8 students.  Has activitives for math, grammar, science, spelling, history.  In the teacher section you are able to search for games by subject/grade including searching by McREL standards.

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This site is designed by teachers for teachers and allows you to create customised interactive versions of popular games (Anagrams, Bingo Game Cards, Blockbusters, Deal or No Deal, Hangman, Millionaire) suitable for students to use during lessons.

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